iommu/amd: Drop oprofile dependency

a40d4c67 ("iommu/amd: Implement mmu_notifier_release call-back")
removed the oprofile task_exit notifier hack^Wusage but forgot to
readjust the Kconfig dependency. Fix that.

Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>